2007-2008 AP Biology

Chemistry of Carbon

Building Blocks of Life

AP Biology

Why study Carbon? All of life is built on carbon Cells

~72% H2O ~25% carbon compounds

_______________ _______________ _______________ _______________

~3% salts Na, Cl, K…

AP Biology

Chemistry of Life Organic chemistry is the study of

carbon compounds C atoms are versatile building blocks

bonding properties 4 stable covalent bonds

HH C

H

H

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Complex molecules assembled like TinkerToys

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Hydrocarbons Combinations of C & H

____________________ not soluble in H2O ____________________

stablevery little attraction

between molecules a gas at room temperature

methane(simplest HC)

AP Biology

Hydrocarbons can grow

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Isomers Molecules with same molecular formula

but different structures (shapes) different chemical properties different biological functions

6 carbons

6 carbons

6 carbons

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Form affects function Structural differences create important

functional significance amino acid alanine

L-alanine used in proteins but not D-alanine

medicines L-version active but not D-version

sometimes withtragic results…

stereoisomers

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Form affects function Thalidomide

prescribed to pregnant women in 50s & 60s reduced morning sickness, but… stereoisomer caused severe birth defects

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Diversity of molecules Substitute other atoms or groups

around the carbon ethane vs. ethanol

H replaced by an hydroxyl group (–OH) nonpolar vs. polar gas vs. liquid biological effects!

ethane (C2H6) ethanol (C2H5OH)

AP Biology

Functional groups Parts of organic molecules that are

involved in chemical reactions give organic molecules distinctive

properties hydroxyl amino carbonyl sulfhydryl carboxyl phosphate

Affect reactivity ___________________________________ increase solubility in water

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Viva la difference! Basic structure of male & female

hormones is identical identical carbon skeleton attachment of different functional groups interact with different targets in the body

different effects

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Hydroxyl –OH

organic compounds with OH = alcohols names typically end in -ol

ethanol

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Carbonyl C=O

O double bonded to C if C=O at end molecule = aldehyde if C=O in middle of molecule = ketone

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Carboxyl –COOH

C double bonded to O & single bonded to OH group compounds with COOH = acids

fatty acidsamino acids

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Amino -NH2

N attached to 2 H compounds with NH2 = amines

amino acids NH2 acts as base

ammonia picks up H+ from solution

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Sulfhydryl –SH

S bonded to H compounds with SH = thiols SH groups stabilize the structure of proteins

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Phosphate –PO4

P bound to 4 O connects to C through an O lots of O = lots of negative charge

highly reactive transfers energy between organic molecules

ATP, GTP, etc.

2007-2008 AP Biology

Macromolecules

Building Blocksof Life

AP Biology

Macromolecules Smaller organic molecules join together

to form larger molecules ____________________

4 major classes of macromolecules: ____________________ ____________________ ____________________ ____________________

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H2O

HO

HO H

H HHO

Polymers Long molecules built by linking repeating

building blocks in a chain ____________________

building blocks repeated small units

____________________

Dehydration synthesis

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H2O

HO

HO H

H HHO

How to build a polymer ____________________

joins monomers by “taking” H2O out one monomer donates OH–

other monomer donates H+ together these form H2O

_______________________

enzymeDehydration synthesisCondensation reaction

You gotta be open to“bonding!

AP Biology

H2O

HO H

HO H HO H

How to break down a polymer ____________________

use H2O to breakdown polymers reverse of dehydration synthesis cleave off one monomer at a time H2O is split into H+ and OH–

H+ & OH– attach to ends __________________ __________________

Breaking upis hard to do!

Hydrolysis

enzyme

Hydrolysis

2007-2008 AP Biology

Any Questions??